Mud-bum, a settlement on the far eastern edge of the Kadmudia Gouche mudflats, is named after its trees. Each mud-bum willow lifts itself high above the mud on a broad tangle of curved roots, each root no thicker than a wrist and often spaced wide apart from its fellows, so that the tree seems to be balancing mainly on air. So thin are those roots that passers-by on the ferryists' rafts tremble to see human beings moving through the branches: oh no, they cry, won't those people fall? The ferryperson feigns disinterest and looks away from the Mud-bum dwellers whom they consider spiritual bastards, rebels against the earth and disdainers of the honest element of water, choosing, as they do, to live in the suspended world of the trees, partway between earth and sky but committed to neither. Those clambering people were ferryists once (so the rumour goes) until they climbed off their rafts, no-one knows why, and into the tangle of branches. The trees held out their leafy hands over the river (here, grab hold, I'll help you up) and up they went. Now they live naked in the loose basket-weave of the mud-bum branches, eating insects, wood-grubs, flowers and the small animals that visit their home.
Individual trees are not strong enough to stand on their own. They link elbows with their neighbours as they grow, and then those elbows grow other elbows, wrists and fingers with which they sieze hold of one another, twisting and twining and knotting together until the colony is one broad labyrinth of branches, a maze without a heart or an exit, through which the sky is clearly visible. Occasionally the outer branches grow a shaggy coat of leaves, but this is rare; usually the foliage comes in tiny, unobtrusive bunches.
When harsh weather threatens them, the Mud-bummians creep inside their round, doorless, twiggy nests, squirming through the walls to the cosy interior where the they curl together in a warm huddle, like hairless baby mice. When the weather is fine they are always outside, climbing about, sunning themselves, hunting for food and speaking in a language of hand gestures.